An ellipse is a plane algebraic curve (sometimes called an oval) where the sum of the distances from any point on the curve to two fixed points is constant. The two fixed points are called foci (plural of focus). An ellipse is also a type of conic section: if a conical surface is cut with a plane which does not intersect the cone's base, the intersection of the cone and plane is an ellipse. The line segment which passes through the foci and terminates on the ellipse is called the major axis. The major axis is the longest segment that passes through the ellipse. The line which passes through the center (halfway between the foci), at right angles to the major axis, is called the minor axis.

 

 

 

An ellipse entity consists of the following data in addition to the Common Data:

 

 

The above properties are shown in the Selection Property Tree when an ellipse entity is selected using the Selection Tool.

 

Click on image to see detail view.

 

To draw an ellipse see the Ellipse Tool.